Shortly after his investiture, Innocent VIII addressed a fruitless summons to
Christendom to unite in a
crusade against the Turks. A protracted conflict with King
Ferdinand I of Naples was the principal obstacle. Ferdinand's oppressive government led in 1485 to a rebellion of the aristocracy, known as the
Conspiracy of the Barons, which included Francesco Coppola and Antonello Sanseverino of Salerno and was supported by Pope Innocent VIII. Innocent excommunicated Ferdinand in 1489 and invited King
Charles VIII of France to come to Italy with an army and take possession of the
Kingdom of Naples. The immediate conflict was not ended until 1494, after Innocent VIII's death.
Relations with the Ottoman Empire Bayezid II ruled as Sultan of the Ottoman Empire from 1481 to 1512. His rule was contested by his brother
Cem, who sought the support of the Mamluks of Egypt. Defeated by his brother's armies, Cem sought protection from the
Knights of St. John in Rhodes. Prince Cem offered perpetual peace between the Ottoman Empire and Christendom. However, the sultan paid the Knights a large amount to keep Cem captive. Cem was later sent to the castle of Pierre d'Aubusson in France. Sultan Bayezid sent a messenger to France and requested Cem to be kept there; he agreed to make an annual payment in gold for his brother's expenses. In March 1489, Cem was transferred to the custody of Innocent VIII. Cem's presence in Rome was useful because whenever Bayezid intended to launch a military campaign against the Christian nations of the
Balkans, the Pope would threaten to release his brother. In exchange for maintaining the custody of Cem, Bayezid paid Innocent VIII 120,000 crowns, a relic of the
Holy Lance and an annual fee of 45,000 ducats. Cem died in Capua on 25 February 1495 on a military expedition under the command of King
Charles VIII of France to conquer Naples.
Relations with witchcraft On the request of German
inquisitor Heinrich Kramer, Innocent VIII issued the
papal bull Summis desiderantes affectibus (5 December 1484), which supported Kramer's investigations against
magicians and
witches: :"It has recently come to our ears, not without great pain to us, that in some parts of upper Germany, [...]
Mainz,
Köln,
Trier,
Salzburg, and
Bremen, many persons of both sexes, heedless of their own salvation and forsaking the catholic faith, give themselves over to devils male and female, and by their incantations, charms, and conjurings, and by other abominable superstitions and sortileges, offences, crimes, and misdeeds, ruin and cause to perish the offspring of women, the foal of animals, the products of the earth, the grapes of vines, and the fruits of trees, as well as men and women, cattle and flocks and herds and animals of every kind, vineyards also and orchards, meadows, pastures, harvests, grains and other fruits of the earth; [...]." The bull was written in response to the request of
Dominican Heinrich Kramer for explicit authority to prosecute witchcraft in Germany, after he was refused assistance by the local ecclesiastical authorities, who disputed his authority to work in their dioceses. Some scholars view the bull as "clearly political", motivated by jurisdictional disputes between the local German Catholic priests and clerics from the Office of the Inquisition who answered more directly to the pope. Nonetheless, the bull failed to ensure that Kramer obtained the support he had hoped for, causing him to retire and to compile his views on witchcraft into his book
Malleus Maleficarum, which was published in 1487. Kramer would later claim that witchcraft was to blame for bad weather. Both the papal letter appended to the work and the supposed endorsement of Cologne University for it are problematic. The letter of Innocent VIII is not an approval of the book to which it was appended, but rather a charge to inquisitors to investigate diabolical sorcery and a warning to those who might impede them in their duty, that is, a papal letter in the by then conventional tradition established by John XXII and other popes through Eugenius IV and Nicholas V (1447–55).
Other events In 1487, Innocent confirmed
Tomas de Torquemada as Grand Inquisitor of
Spain. Also in 1487, Innocent issued a bull
Id Nostri Cordis denouncing the views of the
Waldensians (Vaudois), offering plenary
indulgence to all who should engage in a Crusade against them. Alberto de' Capitanei, archdeacon of
Cremona, responded to the bull by organizing a crusade to fulfill its order and launched an offensive in the provinces of
Dauphiné and
Piedmont.
Charles I, Duke of Savoy eventually interfered to save his territories from further confusion and promised the Vaudois peace, but not before the offensive had devastated the area and many of the Vaudois fled to
Provence and south to Italy. The noted
Franciscan theologian
Angelo Carletti di Chivasso, whom Innocent in 1491 appointed as Apostolic Nuncio and Commissary, conjointly with the
Bishop of Mauriana, was involved in reaching the peaceful agreement between Catholics and Waldensians. In 1486, Innocent VIII was persuaded that at least thirteen of the 900 theses of
Giovanni Pico della Mirandola were heretical, and the book containing the theses was interdicted. In Rome, he ordered the
Belvedere of the Vatican to be built, intended for summer use, on an unarticulated slope above the
Vatican Palace. His successor would later turn the building into the
Cortile del Belvedere. In season, he hunted at Castello della Magliana, which he enlarged. Constantly confronted with a depleted treasury, he resorted to the objectionable expedient of creating new offices and granting them to the highest bidders. In the case of Innocent he permitted trade with
Barbary merchants in which foodstuffs would be given in exchange for slaves who could then be converted to Christianity. The slaves of Innocent were called
mori, meaning "dark-skinned men", in contrast to negro slaves who were called
mori neri, meaning "black moors".
Canonizations In 1484, Innocent granted formal approval for the local veneration of
Catherine of Vadstena, recognizing her cult and affirming her status within the traditions of regional religious devotion—a significant step toward legitimizing her sanctity within the broader framework of the Catholic Church. In 1485, at
Emperor Frederick III's request, Innocent canonized
Leopold III.
Consistories Innocent VIII named eight cardinals in one consistory which was held on 9 March 1489; the pope named three of those cardinals
in pectore (one of whom being a successor in
Giovanni de' Medici who became Pope Leo X) with two of them having their names released after the pope died to ensure that they could vote in the
1492 conclave. ==Death==